My address also shows as "not available", however I was able to get 2 of them. If you boot them up in a working location, then take them back to my address, they work, but temporarily. After a while, they will do exactly what you are describing.
I have since moved them to other locations where they are listed as "available" on that site and they work as they should.
My 'guess' is that you lucked out in getting them to work as long as you did, but recently the loophole has been plugged?